Phycotoxins

Philip F. Solter, Val R. Beasley

Research output: Chapter in Book/Report/Conference proceedingChapter

24 Scopus citations

Abstract

Phycotoxins are potent organic compounds produced by dinoflagellates, other flagellated phytoplankton, and cyanobacteria that inhabit marine, brackish, or freshwater bodies or soils. Among the most important cyanobacterial phycotoxins are microcystins, nodularin, cylindrospermopsin, Lyngbya toxins, anatoxins, saxitoxins, and β-METHYLAMINO-l-ALANINE; the most important marine phycotoxins from diatoms or dinoflagellates include saxitoxins, domoic acid, brevetoxins, and ciguatoxins. At least 100 different species of organisms may harbor toxins. Toxicoses from marine phycotoxin producers in man, other mammals, and birds can occur from direct contact via skin, inhalation, or ingestion of toxigenic organisms or lysates, or by ingestion after passage of the toxins through food chains to shellfish or finfish. Large die-offs of fish may also occur. Concentrated harmful algal blooms (HABs) can color the waters, and some of the marine organisms cause what are known as "red tides." However, clear water may also harbor toxic levels of phycotoxins. Exposure to cyanobacterial toxins in freshwater environments is most frequently through direct consumption of contaminated water, but inhalation or wound absorption is also possible, and with some of the neurotoxins, food chain exposure can be important. Eutrophication of fresh, estuarine, or brackish marine waters can result in massive blooms of toxic cyanobacteria. Excessive nutrient runoff can result from burning, fertilization, overgrazing, herbicide- or tillage-related absence of plant cover, and urban/suburban development. Nutrient loading also frequently arises from additions of animal and human excreta, and atmospheric deposition from fossil fuel burning. Droughts, storms, and/or El Niño events that produce warmer water may shorten generation times of toxigenic cyanobacteria, diatoms, and dinoflagellates, thereby increasing risks. Also, elimination of plants that overhang, live in, or emerge from fresh water allows more UV and infrared to enter water bodies and promote cyanobacterial replication. The effects of different phycotoxins range from peracute lethality from respiratory paralysis to acute liver failure and death, prolonged nervous system damage, skin irritation, and tumor promotion. Analytical methods, such as liquid chromatography/mass spectrometry (LC/MS), immunoassays, and mouse bioassays, have been developed to determine the presence of the phycotoxins in source materials, digestive tract contents, tissues, and seafood. However, presumptive diagnoses of phycotoxin poisonings are frequently made based on a combination of a history of consumption or exposure to a suspected source of toxin, clinical signs, and in some cases compatible lesions. While necropsy and histopathology should be relied upon, the evidence from such examinations is often supportive rather than pathognomonic of a specific phycotoxicosis. © 2013

Original languageEnglish (US)
Title of host publicationHaschek and Rousseaux's Handbook of Toxicologic Pathology
PublisherElsevier Inc.
Pages1155-1186
Number of pages32
ISBN (Print)9780124157590
DOIs
StatePublished - Aug 29 2013

All Science Journal Classification (ASJC) codes

  • Pharmacology, Toxicology and Pharmaceutics(all)

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